This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The National Institute of Standards and Technology has tasked NMRFAM with characterizing and quantifying the most abundant metobolites in human serum. This will be accomplished using 1H-13C HSQC and 1H-1H TOCSY.